The present invention relates to a dual display, and more particularly to a dual display having an imaged perforated film for viewing a first image in a first lighting condition and a projection/diffusion system for viewing a second image or series of images in a second lighting condition.
Advertisers and merchants desire the ability to display graphic and/or informational images on a wide variety of surfaces. In recent years, transparent surfaces such as windows, walls and the like have attracted a great deal of attention as substrates for advertising media. In some applications, graphic images applied to transparent substrates are visible when viewed from one side of the substrate, while leaving the substrate substantially transparent when viewed from the other side of the substrate.
Graphic articles achieving this effect are typically multi-layer films having an opaque (light colored, usually white) film adapted to receive an image on one surface and light absorbing (dark colored, usually black) film or ink applied to the opposite surface. A pressure sensitive adhesive and removable backing, or carrier, material is applied to the dark film or ink, which allows the printed graphic to be handled and applied to a window.
Numerous perforations through the film layers create an optical illusion of “transparency” through the graphic article. The perforations are sized and spaced such that, when observed from the imaged side, a viewer has a tendency to see the image. However, when observed from the relatively darker side, the viewer has a tendency to see through the graphic article, leaving their view unobstructed. In addition, it is well known that windows appear dark or opaque when viewed from an area of relatively bright ambient light into a relatively darker area. When viewed from an area of relatively dark ambient light into a relatively brighter area, the windows appear transparent. The unidirectional effect of the graphic article is enhanced by this effect, which allows viewers in relatively darker areas, such as the interiors of vehicles and buildings, to see through the unidirectional graphic article, while viewers in relatively brighter ambient light will see the printed graphic.
The design and production of a unidirectional graphic article is described in detail in U.S. Pat. No. 6,254,711 entitled “Method for Making Unidirectional Graphic Article” and assigned to the same assignee as the instant application. U.S. Pat. No. 6,254,711 is hereby incorporated by reference in its entirety.
While unidirectional graphic articles are quite useful in a number of display environments, these articles typically provide only one display option in a first lighting condition, and a non-display (transparent) viewing option in a second lighting condition. That is, an image can be seen (from the viewing side of the article) in high brightness conditions such as daylight, and the image is not visible (from the viewing side of the article) in low brightness conditions such as nighttime. Additional, more versatile display systems would also be useful in the art.